含瓦斯抽放钻孔沿空掘巷窄煤柱合理宽度研究

Reasonable width of narrow coal pillars in roadway driving with gas drainage hole

以石泉煤业30108综放工作面轨道巷沿空掘巷为背景,通过理论分析计算了最小煤柱宽度,并采用UDEC软件对不同区域——钻孔段、钻孔延伸段(合称钻场内)、不布置钻孔段内不同宽度(5~20m)煤柱下的弹塑性区和垂直应力分布进行模拟,从而分析了不同条件下围岩稳定性与煤柱承载能力。研究结果表明:①根据岩体极限平衡理论,煤柱最小宽度为8.94m;②在数值模拟中,煤柱宽5,6m时,3种煤柱内的大部分区域处于破坏状态;煤柱宽10m以上时,钻场内煤柱顶底板剪切破坏区域相互贯通;在钻场延伸段8,9m的煤柱应力集中较10m的明显,在钻场内7~9m的煤柱边缘拉伸破坏区域较10m的大。综合理论分析和数值模拟结果,建议煤柱宽度应选为10m。现场实践验证了煤柱宽度的合理性,并取得了显著的经济效益。

Taking the roadway along the 30108 working face of Shiquan Coal Mine,the minimum coal pillar width was calculated by theoretical analysis;UDEC software was used to simulate the distribution of elastoplastic zone and vertical stress distribution different areas(no drilling section or drilling section) under different width(5-20 m) coal pillars in the borehole extension section,and analyze the stability of surrounding rock and bearing capacity of coal pillar under different conditions. The results showed that:according to the theory of limit equilibrium of rock mass, the minimum width of coal pillar is 8.94 m;when the coal pillar is 5,6 m wide,most of the coal pillars are in a state of failure;when the coal pillar is more than 10 m wide,the shear failure zone of the coal pillar top and bottom in the drill field is mutually connected;within the drill field,the 8,9 m coal pillar stress concentration is more obvious than 10 m,the 7-9 m coal pillar edge tensile failure zone is larger than 10 m. Based on comprehensive theoretical analysis and numerical simulation results,it is recommended that the coal pillar width should be chosen to be 10 m. Field practice verified the rationality of the coal pillar width and achieved significant economic benefits.